A) Field of the Invention
The present invention relates to a method of manufacturing an electronic circuit component and, more particularly, to a method of manufacturing an electronic circuit component having a conductor pattern buried in holes or trenches.
An example of such an electronic circuit component is an interposer substrate. For example, when LSIs are mounted on a mother board of a computer, an interposer substrate is interposed between LSIs and the mother board in some cases. If an interposer substrate is formed by an Si substrate, the interposer substrate can be manufactured by utilizing manufacturing techniques of semiconductor devices. When through conductors are formed through layers of IC, LSI, memory or the like, a multilevel circuit can be manufactured.
B) Description of the Related Art
A multi-chip module (MCM) board used with a main frame computer and the like has a plurality of LSls mounted thereon. Capacitors are often mounted on the MCM board in order to eliminate noises from the power supply voltages. Conventionally, a ceramic capacitor chip is mounted on an MCM board.
Recent computers have a high clock frequency. If a ceramic capacitor chip is to be mounted, it becomes necessary to use lead wires. These lead wires have impedance components such as inductance L so that high speed performance is degraded.
In order to improve high speed performance, an interposer substrate mounted with capacitors just under LSIs to be mounted is desired in order to shorten the wiring length. In order to reduce the opposing areas of capacitor electrodes and obtain a large capacitance, it is preferable to use dielectric material having a high dielectric constant as the material of the capacitor dielectric film.
For example, barium strontium titanate (BST, (Ba, Sr)TiO3) is used as the material of the capacitor dielectric film. In order to improve the capacitor characteristics, after the capacitor dielectric film is formed, BST is preferably annealed at about 700° C. in an oxidizing atmosphere such as air. The circuit board is required to be excellent in heat resistance in order to perform high temperature annealing in an oxidizing atmosphere.
Although a ceramic substrate is excellent in heat resistance, it has the problem of scratches on a polished surface and poor smoothness of a substrate surface. When ceramic is baked, it shrinks and the volume is reduced. It is therefore difficult to precisely control a pitch between electrodes or pads.
An interposer substrate made of an Si substrate can utilize the manufacturing techniques of Si integrated circuit devices so that a high precision can be realized. A method of manufacturing a circuit board made of an Si substrate has not established as of yet.